MSTest overview
MSTest, Microsoft Testing Framework, is a test framework for .NET applications. It allows you to write and execute tests, and provide test suites with integration to Visual Studio and Visual Studio Code Test Explorers, the .NET CLI, and many CI pipelines.
MSTest is a fully supported, open-source and a cross-platform test framework that works with all supported .NET targets (.NET Framework, .NET Core, .NET, UWP, WinUI, and so on) hosted on GitHub.
MSTest support policy
Since v3.0.0, MSTest is strictly following semantic versioning.
The MSTest team only supports the latest released version and strongly encourages its users and customers to always update to latest version to benefit from new improvements and security patches. Preview releases aren't supported by Microsoft, but they are offered for public testing ahead of the final release.